Paul Giamati
He should have won the Oscar, just for the last 5 minutes when he pieces everything together in his mind. His facial expressions are dead on.
Wonderful performance throughout the film.
Sadly, there are way too many times when he should have won an Oscar and never has. This is just another on the long list.
He was great in this.
SPOILER. Don't click on this if you haven't seen the movie or you don't want to know the ending.
Here's the ending scene. The reveal on Paul Giamatti's face says it all. Brilliant
https://www.youtube.com/watch?v=-TdTsgXZ2vs